Hi @debajyoti
Can you please ask your server team why they came to this assumption? I am quite interested in what they have found.
Please note that the ACF plugin is simply a GUI interface for data. It is most likely that the 503 error is coming from some troublesome code in your functions.php file, or perhaps a page template.
This could be causing an overload of the server’s memory and would explain why it is shutting down.
Thanks
E